A gasoline-electric hybrid vehicle includes both a gasoline-powered engine and an electric-powered motor. In a parallel hybrid system, the gasoline-powered engine and the electric-powered motor are both coupled to the vehicle's transmission. The resultant hybrid transmission converts the gasoline-powered engine and electric-powered motor output torques to an output torque sufficient to power the vehicle's drive shaft.
Traditionally, as illustrated in FIG. 1, electric-powered motors 130 in a hybrid vehicle 100 have been provided along the same axis as the output shaft 120 of the vehicle's transmission 110. While on-axis positioning may result in certain efficiencies in the transmission of power from the electric motor to the transmission to the vehicle's drive shaft, the size and related output ability of an on-axis electric motor is often constrained by positions of already existing engine components. Thus, the on-axis electric motor is often less powerful than desired, necessitating the inclusion of a second auxiliary electric motor that is used to make up for the shortcomings of the primary electric motor.
Thus, there is a need and a desire to simplify gasoline-electric hybrid vehicles by using an electric-powered motor that provides sufficient power so that the vehicle need only rely upon one electric-powered motor. There is also a need and a desire to be able to convert a traditional transmission in an engine compartment to a hybrid transmission that can couple to an electric-powered motor of sufficient power.